(1):

(a.) Last in a train of progression or consequences; tended toward by all that precedes; arrived at, as the last result; final.

(2):

(a.) Incapable of further analysis; incapable of further division or separation; constituent; elemental; as, an ultimate constituent of matter.

(3):

(a.) Farthest; most remote in space or time; extreme; last; final.

(4):

(v. t. & i.) To come or bring to an end; to eventuate; to end.

(5):

(v. t. & i.) To come or bring into use or practice.